334 



THE BEGINNINGS OF LIFE. 



course of a few minutes each of which, after it has 

 attained a length of about ais", gradually develops a 

 terminal, spherical, or ovoidal dilatation, which becomes 



FIG. 76. 



Mode of Origin of Trichomonas, and its Transformation into Acti- 

 nophrys and Amoeba. (Reduced, from Nicolet.) 



a-e. Different stages in the formation of a germinal globule. 

 /. g. Segmentation of its contents into embryo specimens of Tricbo- 



monas (h, i,j). 



k, I, n. Forms subsequently assumed by these bodies, which, later still, 

 become converted into Actinopbrys (m) or Amceba (o) the 

 latter rapidly increasing in size (/>). 



filled with a granular mucilage, poured into it through 

 the tubular portion l . Soon, however, fluid ceases to 



1 Mr. Archer describes in 'Journal of Microsc. Sc.' 1860, vol. viii. 

 p. 227, the production of somewhat similar tubes from a portion of 

 a large Desmid, through which ciliated zoospores are subsequently dis- 

 charged. These appear to be produced by a breaking up of the endo- 

 chrome of the frustule itself, near the part whence the tube issues. 

 When discharged the zoospores were found to be 3 & OQ " in diameter, and 

 provided with a single cilium. They, in fact, very closely resembled the 

 bodies whose production Mr. Carter had watched within the so-called 



